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Diffstat (limited to 'lib/CodeGen/CGExprScalar.cpp')
| -rw-r--r-- | lib/CodeGen/CGExprScalar.cpp | 1575 |
1 files changed, 1575 insertions, 0 deletions
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp new file mode 100644 index 0000000..950e9e5 --- /dev/null +++ b/lib/CodeGen/CGExprScalar.cpp @@ -0,0 +1,1575 @@ +//===--- CGExprScalar.cpp - Emit LLVM Code for Scalar Exprs ---------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This contains code to emit Expr nodes with scalar LLVM types as LLVM code. +// +//===----------------------------------------------------------------------===// + +#include "CodeGenFunction.h" +#include "CodeGenModule.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/RecordLayout.h" +#include "clang/AST/StmtVisitor.h" +#include "clang/Basic/TargetInfo.h" +#include "llvm/Constants.h" +#include "llvm/Function.h" +#include "llvm/GlobalVariable.h" +#include "llvm/Intrinsics.h" +#include "llvm/Module.h" +#include "llvm/Support/Compiler.h" +#include "llvm/Support/CFG.h" +#include "llvm/Target/TargetData.h" +#include <cstdarg> + +using namespace clang; +using namespace CodeGen; +using llvm::Value; + +//===----------------------------------------------------------------------===// +// Scalar Expression Emitter +//===----------------------------------------------------------------------===// + +struct BinOpInfo { + Value *LHS; + Value *RHS; + QualType Ty; // Computation Type. + const BinaryOperator *E; +}; + +namespace { +class VISIBILITY_HIDDEN ScalarExprEmitter + : public StmtVisitor<ScalarExprEmitter, Value*> { + CodeGenFunction &CGF; + CGBuilderTy &Builder; + bool IgnoreResultAssign; + +public: + + ScalarExprEmitter(CodeGenFunction &cgf, bool ira=false) + : CGF(cgf), Builder(CGF.Builder), IgnoreResultAssign(ira) { + } + + //===--------------------------------------------------------------------===// + // Utilities + //===--------------------------------------------------------------------===// + + bool TestAndClearIgnoreResultAssign() { + bool I = IgnoreResultAssign; IgnoreResultAssign = false; + return I; } + + const llvm::Type *ConvertType(QualType T) { return CGF.ConvertType(T); } + LValue EmitLValue(const Expr *E) { return CGF.EmitLValue(E); } + + Value *EmitLoadOfLValue(LValue LV, QualType T) { + return CGF.EmitLoadOfLValue(LV, T).getScalarVal(); + } + + /// EmitLoadOfLValue - Given an expression with complex type that represents a + /// value l-value, this method emits the address of the l-value, then loads + /// and returns the result. + Value *EmitLoadOfLValue(const Expr *E) { + return EmitLoadOfLValue(EmitLValue(E), E->getType()); + } + + /// EmitConversionToBool - Convert the specified expression value to a + /// boolean (i1) truth value. This is equivalent to "Val != 0". + Value *EmitConversionToBool(Value *Src, QualType DstTy); + + /// EmitScalarConversion - Emit a conversion from the specified type to the + /// specified destination type, both of which are LLVM scalar types. + Value *EmitScalarConversion(Value *Src, QualType SrcTy, QualType DstTy); + + /// EmitComplexToScalarConversion - Emit a conversion from the specified + /// complex type to the specified destination type, where the destination + /// type is an LLVM scalar type. + Value *EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, + QualType SrcTy, QualType DstTy); + + //===--------------------------------------------------------------------===// + // Visitor Methods + //===--------------------------------------------------------------------===// + + Value *VisitStmt(Stmt *S) { + S->dump(CGF.getContext().getSourceManager()); + assert(0 && "Stmt can't have complex result type!"); + return 0; + } + Value *VisitExpr(Expr *S); + Value *VisitParenExpr(ParenExpr *PE) { return Visit(PE->getSubExpr()); } + + // Leaves. + Value *VisitIntegerLiteral(const IntegerLiteral *E) { + return llvm::ConstantInt::get(E->getValue()); + } + Value *VisitFloatingLiteral(const FloatingLiteral *E) { + return llvm::ConstantFP::get(E->getValue()); + } + Value *VisitCharacterLiteral(const CharacterLiteral *E) { + return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); + } + Value *VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { + return llvm::ConstantInt::get(ConvertType(E->getType()), E->getValue()); + } + Value *VisitCXXZeroInitValueExpr(const CXXZeroInitValueExpr *E) { + return llvm::Constant::getNullValue(ConvertType(E->getType())); + } + Value *VisitGNUNullExpr(const GNUNullExpr *E) { + return llvm::Constant::getNullValue(ConvertType(E->getType())); + } + Value *VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { + return llvm::ConstantInt::get(ConvertType(E->getType()), + CGF.getContext().typesAreCompatible( + E->getArgType1(), E->getArgType2())); + } + Value *VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); + Value *VisitAddrLabelExpr(const AddrLabelExpr *E) { + llvm::Value *V = + llvm::ConstantInt::get(llvm::Type::Int32Ty, + CGF.GetIDForAddrOfLabel(E->getLabel())); + + return Builder.CreateIntToPtr(V, ConvertType(E->getType())); + } + + // l-values. + Value *VisitDeclRefExpr(DeclRefExpr *E) { + if (const EnumConstantDecl *EC = dyn_cast<EnumConstantDecl>(E->getDecl())) + return llvm::ConstantInt::get(EC->getInitVal()); + return EmitLoadOfLValue(E); + } + Value *VisitObjCSelectorExpr(ObjCSelectorExpr *E) { + return CGF.EmitObjCSelectorExpr(E); + } + Value *VisitObjCProtocolExpr(ObjCProtocolExpr *E) { + return CGF.EmitObjCProtocolExpr(E); + } + Value *VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { + return EmitLoadOfLValue(E); + } + Value *VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { + return EmitLoadOfLValue(E); + } + Value *VisitObjCKVCRefExpr(ObjCKVCRefExpr *E) { + return EmitLoadOfLValue(E); + } + Value *VisitObjCMessageExpr(ObjCMessageExpr *E) { + return CGF.EmitObjCMessageExpr(E).getScalarVal(); + } + + Value *VisitArraySubscriptExpr(ArraySubscriptExpr *E); + Value *VisitShuffleVectorExpr(ShuffleVectorExpr *E); + Value *VisitMemberExpr(Expr *E) { return EmitLoadOfLValue(E); } + Value *VisitExtVectorElementExpr(Expr *E) { return EmitLoadOfLValue(E); } + Value *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { + return EmitLoadOfLValue(E); + } + Value *VisitStringLiteral(Expr *E) { return EmitLValue(E).getAddress(); } + Value *VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { + return EmitLValue(E).getAddress(); + } + + Value *VisitPredefinedExpr(Expr *E) { return EmitLValue(E).getAddress(); } + + Value *VisitInitListExpr(InitListExpr *E) { + bool Ignore = TestAndClearIgnoreResultAssign(); + (void)Ignore; + assert (Ignore == false && "init list ignored"); + unsigned NumInitElements = E->getNumInits(); + + if (E->hadArrayRangeDesignator()) { + CGF.ErrorUnsupported(E, "GNU array range designator extension"); + } + + const llvm::VectorType *VType = + dyn_cast<llvm::VectorType>(ConvertType(E->getType())); + + // We have a scalar in braces. Just use the first element. + if (!VType) + return Visit(E->getInit(0)); + + unsigned NumVectorElements = VType->getNumElements(); + const llvm::Type *ElementType = VType->getElementType(); + + // Emit individual vector element stores. + llvm::Value *V = llvm::UndefValue::get(VType); + + // Emit initializers + unsigned i; + for (i = 0; i < NumInitElements; ++i) { + Value *NewV = Visit(E->getInit(i)); + Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); + V = Builder.CreateInsertElement(V, NewV, Idx); + } + + // Emit remaining default initializers + for (/* Do not initialize i*/; i < NumVectorElements; ++i) { + Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); + llvm::Value *NewV = llvm::Constant::getNullValue(ElementType); + V = Builder.CreateInsertElement(V, NewV, Idx); + } + + return V; + } + + Value *VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { + return llvm::Constant::getNullValue(ConvertType(E->getType())); + } + Value *VisitImplicitCastExpr(const ImplicitCastExpr *E); + Value *VisitCastExpr(const CastExpr *E) { + // Make sure to evaluate VLA bounds now so that we have them for later. + if (E->getType()->isVariablyModifiedType()) + CGF.EmitVLASize(E->getType()); + + return EmitCastExpr(E->getSubExpr(), E->getType()); + } + Value *EmitCastExpr(const Expr *E, QualType T); + + Value *VisitCallExpr(const CallExpr *E) { + if (E->getCallReturnType()->isReferenceType()) + return EmitLoadOfLValue(E); + + return CGF.EmitCallExpr(E).getScalarVal(); + } + + Value *VisitStmtExpr(const StmtExpr *E); + + Value *VisitBlockDeclRefExpr(const BlockDeclRefExpr *E); + + // Unary Operators. + Value *VisitPrePostIncDec(const UnaryOperator *E, bool isInc, bool isPre); + Value *VisitUnaryPostDec(const UnaryOperator *E) { + return VisitPrePostIncDec(E, false, false); + } + Value *VisitUnaryPostInc(const UnaryOperator *E) { + return VisitPrePostIncDec(E, true, false); + } + Value *VisitUnaryPreDec(const UnaryOperator *E) { + return VisitPrePostIncDec(E, false, true); + } + Value *VisitUnaryPreInc(const UnaryOperator *E) { + return VisitPrePostIncDec(E, true, true); + } + Value *VisitUnaryAddrOf(const UnaryOperator *E) { + return EmitLValue(E->getSubExpr()).getAddress(); + } + Value *VisitUnaryDeref(const Expr *E) { return EmitLoadOfLValue(E); } + Value *VisitUnaryPlus(const UnaryOperator *E) { + // This differs from gcc, though, most likely due to a bug in gcc. + TestAndClearIgnoreResultAssign(); + return Visit(E->getSubExpr()); + } + Value *VisitUnaryMinus (const UnaryOperator *E); + Value *VisitUnaryNot (const UnaryOperator *E); + Value *VisitUnaryLNot (const UnaryOperator *E); + Value *VisitUnaryReal (const UnaryOperator *E); + Value *VisitUnaryImag (const UnaryOperator *E); + Value *VisitUnaryExtension(const UnaryOperator *E) { + return Visit(E->getSubExpr()); + } + Value *VisitUnaryOffsetOf(const UnaryOperator *E); + + // C++ + Value *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { + return Visit(DAE->getExpr()); + } + Value *VisitCXXThisExpr(CXXThisExpr *TE) { + return CGF.LoadCXXThis(); + } + + Value *VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { + return CGF.EmitCXXExprWithTemporaries(E).getScalarVal(); + } + Value *VisitCXXNewExpr(const CXXNewExpr *E) { + return CGF.EmitCXXNewExpr(E); + } + + // Binary Operators. + Value *EmitMul(const BinOpInfo &Ops) { + if (CGF.getContext().getLangOptions().OverflowChecking + && Ops.Ty->isSignedIntegerType()) + return EmitOverflowCheckedBinOp(Ops); + return Builder.CreateMul(Ops.LHS, Ops.RHS, "mul"); + } + /// Create a binary op that checks for overflow. + /// Currently only supports +, - and *. + Value *EmitOverflowCheckedBinOp(const BinOpInfo &Ops); + Value *EmitDiv(const BinOpInfo &Ops); + Value *EmitRem(const BinOpInfo &Ops); + Value *EmitAdd(const BinOpInfo &Ops); + Value *EmitSub(const BinOpInfo &Ops); + Value *EmitShl(const BinOpInfo &Ops); + Value *EmitShr(const BinOpInfo &Ops); + Value *EmitAnd(const BinOpInfo &Ops) { + return Builder.CreateAnd(Ops.LHS, Ops.RHS, "and"); + } + Value *EmitXor(const BinOpInfo &Ops) { + return Builder.CreateXor(Ops.LHS, Ops.RHS, "xor"); + } + Value *EmitOr (const BinOpInfo &Ops) { + return Builder.CreateOr(Ops.LHS, Ops.RHS, "or"); + } + + BinOpInfo EmitBinOps(const BinaryOperator *E); + Value *EmitCompoundAssign(const CompoundAssignOperator *E, + Value *(ScalarExprEmitter::*F)(const BinOpInfo &)); + + // Binary operators and binary compound assignment operators. +#define HANDLEBINOP(OP) \ + Value *VisitBin ## OP(const BinaryOperator *E) { \ + return Emit ## OP(EmitBinOps(E)); \ + } \ + Value *VisitBin ## OP ## Assign(const CompoundAssignOperator *E) { \ + return EmitCompoundAssign(E, &ScalarExprEmitter::Emit ## OP); \ + } + HANDLEBINOP(Mul); + HANDLEBINOP(Div); + HANDLEBINOP(Rem); + HANDLEBINOP(Add); + HANDLEBINOP(Sub); + HANDLEBINOP(Shl); + HANDLEBINOP(Shr); + HANDLEBINOP(And); + HANDLEBINOP(Xor); + HANDLEBINOP(Or); +#undef HANDLEBINOP + + // Comparisons. + Value *EmitCompare(const BinaryOperator *E, unsigned UICmpOpc, + unsigned SICmpOpc, unsigned FCmpOpc); +#define VISITCOMP(CODE, UI, SI, FP) \ + Value *VisitBin##CODE(const BinaryOperator *E) { \ + return EmitCompare(E, llvm::ICmpInst::UI, llvm::ICmpInst::SI, \ + llvm::FCmpInst::FP); } + VISITCOMP(LT, ICMP_ULT, ICMP_SLT, FCMP_OLT); + VISITCOMP(GT, ICMP_UGT, ICMP_SGT, FCMP_OGT); + VISITCOMP(LE, ICMP_ULE, ICMP_SLE, FCMP_OLE); + VISITCOMP(GE, ICMP_UGE, ICMP_SGE, FCMP_OGE); + VISITCOMP(EQ, ICMP_EQ , ICMP_EQ , FCMP_OEQ); + VISITCOMP(NE, ICMP_NE , ICMP_NE , FCMP_UNE); +#undef VISITCOMP + + Value *VisitBinAssign (const BinaryOperator *E); + + Value *VisitBinLAnd (const BinaryOperator *E); + Value *VisitBinLOr (const BinaryOperator *E); + Value *VisitBinComma (const BinaryOperator *E); + + // Other Operators. + Value *VisitBlockExpr(const BlockExpr *BE); + Value *VisitConditionalOperator(const ConditionalOperator *CO); + Value *VisitChooseExpr(ChooseExpr *CE); + Value *VisitVAArgExpr(VAArgExpr *VE); + Value *VisitObjCStringLiteral(const ObjCStringLiteral *E) { + return CGF.EmitObjCStringLiteral(E); + } +}; +} // end anonymous namespace. + +//===----------------------------------------------------------------------===// +// Utilities +//===----------------------------------------------------------------------===// + +/// EmitConversionToBool - Convert the specified expression value to a +/// boolean (i1) truth value. This is equivalent to "Val != 0". +Value *ScalarExprEmitter::EmitConversionToBool(Value *Src, QualType SrcType) { + assert(SrcType->isCanonical() && "EmitScalarConversion strips typedefs"); + + if (SrcType->isRealFloatingType()) { + // Compare against 0.0 for fp scalars. + llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); + return Builder.CreateFCmpUNE(Src, Zero, "tobool"); + } + + assert((SrcType->isIntegerType() || isa<llvm::PointerType>(Src->getType())) && + "Unknown scalar type to convert"); + + // Because of the type rules of C, we often end up computing a logical value, + // then zero extending it to int, then wanting it as a logical value again. + // Optimize this common case. + if (llvm::ZExtInst *ZI = dyn_cast<llvm::ZExtInst>(Src)) { + if (ZI->getOperand(0)->getType() == llvm::Type::Int1Ty) { + Value *Result = ZI->getOperand(0); + // If there aren't any more uses, zap the instruction to save space. + // Note that there can be more uses, for example if this + // is the result of an assignment. + if (ZI->use_empty()) + ZI->eraseFromParent(); + return Result; + } + } + + // Compare against an integer or pointer null. + llvm::Value *Zero = llvm::Constant::getNullValue(Src->getType()); + return Builder.CreateICmpNE(Src, Zero, "tobool"); +} + +/// EmitScalarConversion - Emit a conversion from the specified type to the +/// specified destination type, both of which are LLVM scalar types. +Value *ScalarExprEmitter::EmitScalarConversion(Value *Src, QualType SrcType, + QualType DstType) { + SrcType = CGF.getContext().getCanonicalType(SrcType); + DstType = CGF.getContext().getCanonicalType(DstType); + if (SrcType == DstType) return Src; + + if (DstType->isVoidType()) return 0; + + // Handle conversions to bool first, they are special: comparisons against 0. + if (DstType->isBooleanType()) + return EmitConversionToBool(Src, SrcType); + + const llvm::Type *DstTy = ConvertType(DstType); + + // Ignore conversions like int -> uint. + if (Src->getType() == DstTy) + return Src; + + // Handle pointer conversions next: pointers can only be converted + // to/from other pointers and integers. Check for pointer types in + // terms of LLVM, as some native types (like Obj-C id) may map to a + // pointer type. + if (isa<llvm::PointerType>(DstTy)) { + // The source value may be an integer, or a pointer. + if (isa<llvm::PointerType>(Src->getType())) + return Builder.CreateBitCast(Src, DstTy, "conv"); + assert(SrcType->isIntegerType() && "Not ptr->ptr or int->ptr conversion?"); + // First, convert to the correct width so that we control the kind of + // extension. + const llvm::Type *MiddleTy = llvm::IntegerType::get(CGF.LLVMPointerWidth); + bool InputSigned = SrcType->isSignedIntegerType(); + llvm::Value* IntResult = + Builder.CreateIntCast(Src, MiddleTy, InputSigned, "conv"); + // Then, cast to pointer. + return Builder.CreateIntToPtr(IntResult, DstTy, "conv"); + } + + if (isa<llvm::PointerType>(Src->getType())) { + // Must be an ptr to int cast. + assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?"); + return Builder.CreatePtrToInt(Src, DstTy, "conv"); + } + + // A scalar can be splatted to an extended vector of the same element type + if (DstType->isExtVectorType() && !isa<VectorType>(SrcType)) { + // Cast the scalar to element type + QualType EltTy = DstType->getAsExtVectorType()->getElementType(); + llvm::Value *Elt = EmitScalarConversion(Src, SrcType, EltTy); + + // Insert the element in element zero of an undef vector + llvm::Value *UnV = llvm::UndefValue::get(DstTy); + llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0); + UnV = Builder.CreateInsertElement(UnV, Elt, Idx, "tmp"); + + // Splat the element across to all elements + llvm::SmallVector<llvm::Constant*, 16> Args; + unsigned NumElements = cast<llvm::VectorType>(DstTy)->getNumElements(); + for (unsigned i = 0; i < NumElements; i++) + Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0)); + + llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); + llvm::Value *Yay = Builder.CreateShuffleVector(UnV, UnV, Mask, "splat"); + return Yay; + } + + // Allow bitcast from vector to integer/fp of the same size. + if (isa<llvm::VectorType>(Src->getType()) || + isa<llvm::VectorType>(DstTy)) + return Builder.CreateBitCast(Src, DstTy, "conv"); + + // Finally, we have the arithmetic types: real int/float. + if (isa<llvm::IntegerType>(Src->getType())) { + bool InputSigned = SrcType->isSignedIntegerType(); + if (isa<llvm::IntegerType>(DstTy)) + return Builder.CreateIntCast(Src, DstTy, InputSigned, "conv"); + else if (InputSigned) + return Builder.CreateSIToFP(Src, DstTy, "conv"); + else + return Builder.CreateUIToFP(Src, DstTy, "conv"); + } + + assert(Src->getType()->isFloatingPoint() && "Unknown real conversion"); + if (isa<llvm::IntegerType>(DstTy)) { + if (DstType->isSignedIntegerType()) + return Builder.CreateFPToSI(Src, DstTy, "conv"); + else + return Builder.CreateFPToUI(Src, DstTy, "conv"); + } + + assert(DstTy->isFloatingPoint() && "Unknown real conversion"); + if (DstTy->getTypeID() < Src->getType()->getTypeID()) + return Builder.CreateFPTrunc(Src, DstTy, "conv"); + else + return Builder.CreateFPExt(Src, DstTy, "conv"); +} + +/// EmitComplexToScalarConversion - Emit a conversion from the specified +/// complex type to the specified destination type, where the destination +/// type is an LLVM scalar type. +Value *ScalarExprEmitter:: +EmitComplexToScalarConversion(CodeGenFunction::ComplexPairTy Src, + QualType SrcTy, QualType DstTy) { + // Get the source element type. + SrcTy = SrcTy->getAsComplexType()->getElementType(); + + // Handle conversions to bool first, they are special: comparisons against 0. + if (DstTy->isBooleanType()) { + // Complex != 0 -> (Real != 0) | (Imag != 0) + Src.first = EmitScalarConversion(Src.first, SrcTy, DstTy); + Src.second = EmitScalarConversion(Src.second, SrcTy, DstTy); + return Builder.CreateOr(Src.first, Src.second, "tobool"); + } + + // C99 6.3.1.7p2: "When a value of complex type is converted to a real type, + // the imaginary part of the complex value is discarded and the value of the + // real part is converted according to the conversion rules for the + // corresponding real type. + return EmitScalarConversion(Src.first, SrcTy, DstTy); +} + + +//===----------------------------------------------------------------------===// +// Visitor Methods +//===----------------------------------------------------------------------===// + +Value *ScalarExprEmitter::VisitExpr(Expr *E) { + CGF.ErrorUnsupported(E, "scalar expression"); + if (E->getType()->isVoidType()) + return 0; + return llvm::UndefValue::get(CGF.ConvertType(E->getType())); +} + +Value *ScalarExprEmitter::VisitShuffleVectorExpr(ShuffleVectorExpr *E) { + llvm::SmallVector<llvm::Constant*, 32> indices; + for (unsigned i = 2; i < E->getNumSubExprs(); i++) { + indices.push_back(cast<llvm::Constant>(CGF.EmitScalarExpr(E->getExpr(i)))); + } + Value* V1 = CGF.EmitScalarExpr(E->getExpr(0)); + Value* V2 = CGF.EmitScalarExpr(E->getExpr(1)); + Value* SV = llvm::ConstantVector::get(indices.begin(), indices.size()); + return Builder.CreateShuffleVector(V1, V2, SV, "shuffle"); +} + +Value *ScalarExprEmitter::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { + TestAndClearIgnoreResultAssign(); + + // Emit subscript expressions in rvalue context's. For most cases, this just + // loads the lvalue formed by the subscript expr. However, we have to be + // careful, because the base of a vector subscript is occasionally an rvalue, + // so we can't get it as an lvalue. + if (!E->getBase()->getType()->isVectorType()) + return EmitLoadOfLValue(E); + + // Handle the vector case. The base must be a vector, the index must be an + // integer value. + Value *Base = Visit(E->getBase()); + Value *Idx = Visit(E->getIdx()); + bool IdxSigned = E->getIdx()->getType()->isSignedIntegerType(); + Idx = Builder.CreateIntCast(Idx, llvm::Type::Int32Ty, IdxSigned, + "vecidxcast"); + return Builder.CreateExtractElement(Base, Idx, "vecext"); +} + +/// VisitImplicitCastExpr - Implicit casts are the same as normal casts, but +/// also handle things like function to pointer-to-function decay, and array to +/// pointer decay. +Value *ScalarExprEmitter::VisitImplicitCastExpr(const ImplicitCastExpr *E) { + const Expr *Op = E->getSubExpr(); + + // If this is due to array->pointer conversion, emit the array expression as + // an l-value. + if (Op->getType()->isArrayType()) { + Value *V = EmitLValue(Op).getAddress(); // Bitfields can't be arrays. + + // Note that VLA pointers are always decayed, so we don't need to do + // anything here. + if (!Op->getType()->isVariableArrayType()) { + assert(isa<llvm::PointerType>(V->getType()) && "Expected pointer"); + assert(isa<llvm::ArrayType>(cast<llvm::PointerType>(V->getType()) + ->getElementType()) && + "Expected pointer to array"); + V = Builder.CreateStructGEP(V, 0, "arraydecay"); + } + + // The resultant pointer type can be implicitly casted to other pointer + // types as well (e.g. void*) and can be implicitly converted to integer. + const llvm::Type *DestTy = ConvertType(E->getType()); + if (V->getType() != DestTy) { + if (isa<llvm::PointerType>(DestTy)) + V = Builder.CreateBitCast(V, DestTy, "ptrconv"); + else { + assert(isa<llvm::IntegerType>(DestTy) && "Unknown array decay"); + V = Builder.CreatePtrToInt(V, DestTy, "ptrconv"); + } + } + return V; + } + + return EmitCastExpr(Op, E->getType()); +} + + +// VisitCastExpr - Emit code for an explicit or implicit cast. Implicit casts +// have to handle a more broad range of conversions than explicit casts, as they +// handle things like function to ptr-to-function decay etc. +Value *ScalarExprEmitter::EmitCastExpr(const Expr *E, QualType DestTy) { + if (!DestTy->isVoidType()) + TestAndClearIgnoreResultAssign(); + + // Handle cases where the source is an non-complex type. + + if (!CGF.hasAggregateLLVMType(E->getType())) { + Value *Src = Visit(const_cast<Expr*>(E)); + + // Use EmitScalarConversion to perform the conversion. + return EmitScalarConversion(Src, E->getType(), DestTy); + } + + if (E->getType()->isAnyComplexType()) { + // Handle cases where the source is a complex type. + bool IgnoreImag = true; + bool IgnoreImagAssign = true; + bool IgnoreReal = IgnoreResultAssign; + bool IgnoreRealAssign = IgnoreResultAssign; + if (DestTy->isBooleanType()) + IgnoreImagAssign = IgnoreImag = false; + else if (DestTy->isVoidType()) { + IgnoreReal = IgnoreImag = false; + IgnoreRealAssign = IgnoreImagAssign = true; + } + CodeGenFunction::ComplexPairTy V + = CGF.EmitComplexExpr(E, IgnoreReal, IgnoreImag, IgnoreRealAssign, + IgnoreImagAssign); + return EmitComplexToScalarConversion(V, E->getType(), DestTy); + } + + // Okay, this is a cast from an aggregate. It must be a cast to void. Just + // evaluate the result and return. + CGF.EmitAggExpr(E, 0, false, true); + return 0; +} + +Value *ScalarExprEmitter::VisitStmtExpr(const StmtExpr *E) { + return CGF.EmitCompoundStmt(*E->getSubStmt(), + !E->getType()->isVoidType()).getScalarVal(); +} + +Value *ScalarExprEmitter::VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { + return Builder.CreateLoad(CGF.GetAddrOfBlockDecl(E), false, "tmp"); +} + +//===----------------------------------------------------------------------===// +// Unary Operators +//===----------------------------------------------------------------------===// + +Value *ScalarExprEmitter::VisitPrePostIncDec(const UnaryOperator *E, + bool isInc, bool isPre) { + LValue LV = EmitLValue(E->getSubExpr()); + QualType ValTy = E->getSubExpr()->getType(); + Value *InVal = CGF.EmitLoadOfLValue(LV, ValTy).getScalarVal(); + + int AmountVal = isInc ? 1 : -1; + + if (ValTy->isPointerType() && + ValTy->getAsPointerType()->isVariableArrayType()) { + // The amount of the addition/subtraction needs to account for the VLA size + CGF.ErrorUnsupported(E, "VLA pointer inc/dec"); + } + + Value *NextVal; + if (const llvm::PointerType *PT = + dyn_cast<llvm::PointerType>(InVal->getType())) { + llvm::Constant *Inc =llvm::ConstantInt::get(llvm::Type::Int32Ty, AmountVal); + if (!isa<llvm::FunctionType>(PT->getElementType())) { + NextVal = Builder.CreateGEP(InVal, Inc, "ptrincdec"); + } else { + const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); + NextVal = Builder.CreateBitCast(InVal, i8Ty, "tmp"); + NextVal = Builder.CreateGEP(NextVal, Inc, "ptrincdec"); + NextVal = Builder.CreateBitCast(NextVal, InVal->getType()); + } + } else if (InVal->getType() == llvm::Type::Int1Ty && isInc) { + // Bool++ is an interesting case, due to promotion rules, we get: + // Bool++ -> Bool = Bool+1 -> Bool = (int)Bool+1 -> + // Bool = ((int)Bool+1) != 0 + // An interesting aspect of this is that increment is always true. + // Decrement does not have this property. + NextVal = llvm::ConstantInt::getTrue(); + } else { + // Add the inc/dec to the real part. + if (isa<llvm::IntegerType>(InVal->getType())) + NextVal = llvm::ConstantInt::get(InVal->getType(), AmountVal); + else if (InVal->getType() == llvm::Type::FloatTy) + NextVal = + llvm::ConstantFP::get(llvm::APFloat(static_cast<float>(AmountVal))); + else if (InVal->getType() == llvm::Type::DoubleTy) + NextVal = + llvm::ConstantFP::get(llvm::APFloat(static_cast<double>(AmountVal))); + else { + llvm::APFloat F(static_cast<float>(AmountVal)); + bool ignored; + F.convert(CGF.Target.getLongDoubleFormat(), llvm::APFloat::rmTowardZero, + &ignored); + NextVal = llvm::ConstantFP::get(F); + } + NextVal = Builder.CreateAdd(InVal, NextVal, isInc ? "inc" : "dec"); + } + + // Store the updated result through the lvalue. + if (LV.isBitfield()) + CGF.EmitStoreThroughBitfieldLValue(RValue::get(NextVal), LV, ValTy, + &NextVal); + else + CGF.EmitStoreThroughLValue(RValue::get(NextVal), LV, ValTy); + + // If this is a postinc, return the value read from memory, otherwise use the + // updated value. + return isPre ? NextVal : InVal; +} + + +Value *ScalarExprEmitter::VisitUnaryMinus(const UnaryOperator *E) { + TestAndClearIgnoreResultAssign(); + Value *Op = Visit(E->getSubExpr()); + return Builder.CreateNeg(Op, "neg"); +} + +Value *ScalarExprEmitter::VisitUnaryNot(const UnaryOperator *E) { + TestAndClearIgnoreResultAssign(); + Value *Op = Visit(E->getSubExpr()); + return Builder.CreateNot(Op, "neg"); +} + +Value *ScalarExprEmitter::VisitUnaryLNot(const UnaryOperator *E) { + // Compare operand to zero. + Value *BoolVal = CGF.EvaluateExprAsBool(E->getSubExpr()); + + // Invert value. + // TODO: Could dynamically modify easy computations here. For example, if + // the operand is an icmp ne, turn into icmp eq. + BoolVal = Builder.CreateNot(BoolVal, "lnot"); + + // ZExt result to the expr type. + return Builder.CreateZExt(BoolVal, ConvertType(E->getType()), "lnot.ext"); +} + +/// VisitSizeOfAlignOfExpr - Return the size or alignment of the type of +/// argument of the sizeof expression as an integer. +Value * +ScalarExprEmitter::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { + QualType TypeToSize = E->getTypeOfArgument(); + if (E->isSizeOf()) { + if (const VariableArrayType *VAT = + CGF.getContext().getAsVariableArrayType(TypeToSize)) { + if (E->isArgumentType()) { + // sizeof(type) - make sure to emit the VLA size. + CGF.EmitVLASize(TypeToSize); + } else { + // C99 6.5.3.4p2: If the argument is an expression of type + // VLA, it is evaluated. + CGF.EmitAnyExpr(E->getArgumentExpr()); + } + + return CGF.GetVLASize(VAT); + } + } + + // If this isn't sizeof(vla), the result must be constant; use the + // constant folding logic so we don't have to duplicate it here. + Expr::EvalResult Result; + E->Evaluate(Result, CGF.getContext()); + return llvm::ConstantInt::get(Result.Val.getInt()); +} + +Value *ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *E) { + Expr *Op = E->getSubExpr(); + if (Op->getType()->isAnyComplexType()) + return CGF.EmitComplexExpr(Op, false, true, false, true).first; + return Visit(Op); +} +Value *ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *E) { + Expr *Op = E->getSubExpr(); + if (Op->getType()->isAnyComplexType()) + return CGF.EmitComplexExpr(Op, true, false, true, false).second; + + // __imag on a scalar returns zero. Emit the subexpr to ensure side + // effects are evaluated, but not the actual value. + if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) + CGF.EmitLValue(Op); + else + CGF.EmitScalarExpr(Op, true); + return llvm::Constant::getNullValue(ConvertType(E->getType())); +} + +Value *ScalarExprEmitter::VisitUnaryOffsetOf(const UnaryOperator *E) +{ + Value* ResultAsPtr = EmitLValue(E->getSubExpr()).getAddress(); + const llvm::Type* ResultType = ConvertType(E->getType()); + return Builder.CreatePtrToInt(ResultAsPtr, ResultType, "offsetof"); +} + +//===----------------------------------------------------------------------===// +// Binary Operators +//===----------------------------------------------------------------------===// + +BinOpInfo ScalarExprEmitter::EmitBinOps(const BinaryOperator *E) { + TestAndClearIgnoreResultAssign(); + BinOpInfo Result; + Result.LHS = Visit(E->getLHS()); + Result.RHS = Visit(E->getRHS()); + Result.Ty = E->getType(); + Result.E = E; + return Result; +} + +Value *ScalarExprEmitter::EmitCompoundAssign(const CompoundAssignOperator *E, + Value *(ScalarExprEmitter::*Func)(const BinOpInfo &)) { + bool Ignore = TestAndClearIgnoreResultAssign(); + QualType LHSTy = E->getLHS()->getType(), RHSTy = E->getRHS()->getType(); + + BinOpInfo OpInfo; + + if (E->getComputationResultType()->isAnyComplexType()) { + // This needs to go through the complex expression emitter, but + // it's a tad complicated to do that... I'm leaving it out for now. + // (Note that we do actually need the imaginary part of the RHS for + // multiplication and division.) + CGF.ErrorUnsupported(E, "complex compound assignment"); + return llvm::UndefValue::get(CGF.ConvertType(E->getType())); + } + + // Emit the RHS first. __block variables need to have the rhs evaluated + // first, plus this should improve codegen a little. + OpInfo.RHS = Visit(E->getRHS()); + OpInfo.Ty = E->getComputationResultType(); + OpInfo.E = E; + // Load/convert the LHS. + LValue LHSLV = EmitLValue(E->getLHS()); + OpInfo.LHS = EmitLoadOfLValue(LHSLV, LHSTy); + OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy, + E->getComputationLHSType()); + + // Expand the binary operator. + Value *Result = (this->*Func)(OpInfo); + + // Convert the result back to the LHS type. + Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy); + + // Store the result value into the LHS lvalue. Bit-fields are + // handled specially because the result is altered by the store, + // i.e., [C99 6.5.16p1] 'An assignment expression has the value of + // the left operand after the assignment...'. + if (LHSLV.isBitfield()) { + if (!LHSLV.isVolatileQualified()) { + CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy, + &Result); + return Result; + } else + CGF.EmitStoreThroughBitfieldLValue(RValue::get(Result), LHSLV, LHSTy); + } else + CGF.EmitStoreThroughLValue(RValue::get(Result), LHSLV, LHSTy); + if (Ignore) + return 0; + return EmitLoadOfLValue(LHSLV, E->getType()); +} + + +Value *ScalarExprEmitter::EmitDiv(const BinOpInfo &Ops) { + if (Ops.LHS->getType()->isFPOrFPVector()) + return Builder.CreateFDiv(Ops.LHS, Ops.RHS, "div"); + else if (Ops.Ty->isUnsignedIntegerType()) + return Builder.CreateUDiv(Ops.LHS, Ops.RHS, "div"); + else + return Builder.CreateSDiv(Ops.LHS, Ops.RHS, "div"); +} + +Value *ScalarExprEmitter::EmitRem(const BinOpInfo &Ops) { + // Rem in C can't be a floating point type: C99 6.5.5p2. + if (Ops.Ty->isUnsignedIntegerType()) + return Builder.CreateURem(Ops.LHS, Ops.RHS, "rem"); + else + return Builder.CreateSRem(Ops.LHS, Ops.RHS, "rem"); +} + +Value *ScalarExprEmitter::EmitOverflowCheckedBinOp(const BinOpInfo &Ops) { + unsigned IID; + unsigned OpID = 0; + + switch (Ops.E->getOpcode()) { + case BinaryOperator::Add: + case BinaryOperator::AddAssign: + OpID = 1; + IID = llvm::Intrinsic::sadd_with_overflow; + break; + case BinaryOperator::Sub: + case BinaryOperator::SubAssign: + OpID = 2; + IID = llvm::Intrinsic::ssub_with_overflow; + break; + case BinaryOperator::Mul: + case BinaryOperator::MulAssign: + OpID = 3; + IID = llvm::Intrinsic::smul_with_overflow; + break; + default: + assert(false && "Unsupported operation for overflow detection"); + IID = 0; + } + OpID <<= 1; + OpID |= 1; + + const llvm::Type *opTy = CGF.CGM.getTypes().ConvertType(Ops.Ty); + + llvm::Function *intrinsic = CGF.CGM.getIntrinsic(IID, &opTy, 1); + + Value *resultAndOverflow = Builder.CreateCall2(intrinsic, Ops.LHS, Ops.RHS); + Value *result = Builder.CreateExtractValue(resultAndOverflow, 0); + Value *overflow = Builder.CreateExtractValue(resultAndOverflow, 1); + + // Branch in case of overflow. + llvm::BasicBlock *initialBB = Builder.GetInsertBlock(); + llvm::BasicBlock *overflowBB = + CGF.createBasicBlock("overflow", CGF.CurFn); + llvm::BasicBlock *continueBB = + CGF.createBasicBlock("overflow.continue", CGF.CurFn); + + Builder.CreateCondBr(overflow, overflowBB, continueBB); + + // Handle overflow + + Builder.SetInsertPoint(overflowBB); + + // Handler is: + // long long *__overflow_handler)(long long a, long long b, char op, + // char width) + std::vector<const llvm::Type*> handerArgTypes; + handerArgTypes.push_back(llvm::Type::Int64Ty); + handerArgTypes.push_back(llvm::Type::Int64Ty); + handerArgTypes.push_back(llvm::Type::Int8Ty); + handerArgTypes.push_back(llvm::Type::Int8Ty); + llvm::FunctionType *handlerTy = llvm::FunctionType::get(llvm::Type::Int64Ty, + handerArgTypes, false); + llvm::Value *handlerFunction = + CGF.CGM.getModule().getOrInsertGlobal("__overflow_handler", + llvm::PointerType::getUnqual(handlerTy)); + handlerFunction = Builder.CreateLoad(handlerFunction); + + llvm::Value *handlerResult = Builder.CreateCall4(handlerFunction, + Builder.CreateSExt(Ops.LHS, llvm::Type::Int64Ty), + Builder.CreateSExt(Ops.RHS, llvm::Type::Int64Ty), + llvm::ConstantInt::get(llvm::Type::Int8Ty, OpID), + llvm::ConstantInt::get(llvm::Type::Int8Ty, + cast<llvm::IntegerType>(opTy)->getBitWidth())); + + handlerResult = Builder.CreateTrunc(handlerResult, opTy); + + Builder.CreateBr(continueBB); + + // Set up the continuation + Builder.SetInsertPoint(continueBB); + // Get the correct result + llvm::PHINode *phi = Builder.CreatePHI(opTy); + phi->reserveOperandSpace(2); + phi->addIncoming(result, initialBB); + phi->addIncoming(handlerResult, overflowBB); + + return phi; +} + +Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { + if (!Ops.Ty->isPointerType()) { + if (CGF.getContext().getLangOptions().OverflowChecking + && Ops.Ty->isSignedIntegerType()) + return EmitOverflowCheckedBinOp(Ops); + return Builder.CreateAdd(Ops.LHS, Ops.RHS, "add"); + } + + if (Ops.Ty->getAsPointerType()->isVariableArrayType()) { + // The amount of the addition needs to account for the VLA size + CGF.ErrorUnsupported(Ops.E, "VLA pointer addition"); + } + Value *Ptr, *Idx; + Expr *IdxExp; + const PointerType *PT; + if ((PT = Ops.E->getLHS()->getType()->getAsPointerType())) { + Ptr = Ops.LHS; + Idx = Ops.RHS; + IdxExp = Ops.E->getRHS(); + } else { // int + pointer + PT = Ops.E->getRHS()->getType()->getAsPointerType(); + assert(PT && "Invalid add expr"); + Ptr = Ops.RHS; + Idx = Ops.LHS; + IdxExp = Ops.E->getLHS(); + } + + unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); + if (Width < CGF.LLVMPointerWidth) { + // Zero or sign extend the pointer value based on whether the index is + // signed or not. + const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); + if (IdxExp->getType()->isSignedIntegerType()) + Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); + else + Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); + } + + const QualType ElementType = PT->getPointeeType(); + // Handle interface types, which are not represented with a concrete + // type. + if (const ObjCInterfaceType *OIT = dyn_cast<ObjCInterfaceType>(ElementType)) { + llvm::Value *InterfaceSize = + llvm::ConstantInt::get(Idx->getType(), + CGF.getContext().getTypeSize(OIT) / 8); + Idx = Builder.CreateMul(Idx, InterfaceSize); + const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); + Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); + Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); + return Builder.CreateBitCast(Res, Ptr->getType()); + } + + // Explicitly handle GNU void* and function pointer arithmetic + // extensions. The GNU void* casts amount to no-ops since our void* + // type is i8*, but this is future proof. + if (ElementType->isVoidType() || ElementType->isFunctionType()) { + const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); + Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); + Value *Res = Builder.CreateGEP(Casted, Idx, "add.ptr"); + return Builder.CreateBitCast(Res, Ptr->getType()); + } + + return Builder.CreateGEP(Ptr, Idx, "add.ptr"); +} + +Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { + if (!isa<llvm::PointerType>(Ops.LHS->getType())) { + if (CGF.getContext().getLangOptions().OverflowChecking + && Ops.Ty->isSignedIntegerType()) + return EmitOverflowCheckedBinOp(Ops); + return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); + } + + if (Ops.E->getLHS()->getType()->getAsPointerType()->isVariableArrayType()) { + // The amount of the addition needs to account for the VLA size for + // ptr-int + // The amount of the division needs to account for the VLA size for + // ptr-ptr. + CGF.ErrorUnsupported(Ops.E, "VLA pointer subtraction"); + } + + const QualType LHSType = Ops.E->getLHS()->getType(); + const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); + if (!isa<llvm::PointerType>(Ops.RHS->getType())) { + // pointer - int + Value *Idx = Ops.RHS; + unsigned Width = cast<llvm::IntegerType>(Idx->getType())->getBitWidth(); + if (Width < CGF.LLVMPointerWidth) { + // Zero or sign extend the pointer value based on whether the index is + // signed or not. + const llvm::Type *IdxType = llvm::IntegerType::get(CGF.LLVMPointerWidth); + if (Ops.E->getRHS()->getType()->isSignedIntegerType()) + Idx = Builder.CreateSExt(Idx, IdxType, "idx.ext"); + else + Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); + } + Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); + + // Handle interface types, which are not represented with a concrete + // type. + if (const ObjCInterfaceType *OIT = + dyn_cast<ObjCInterfaceType>(LHSElementType)) { + llvm::Value *InterfaceSize = + llvm::ConstantInt::get(Idx->getType(), + CGF.getContext().getTypeSize(OIT) / 8); + Idx = Builder.CreateMul(Idx, InterfaceSize); + const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); + Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); + Value *Res = Builder.CreateGEP(LHSCasted, Idx, "add.ptr"); + return Builder.CreateBitCast(Res, Ops.LHS->getType()); + } + + // Explicitly handle GNU void* and function pointer arithmetic + // extensions. The GNU void* casts amount to no-ops since our + // void* type is i8*, but this is future proof. + if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { + const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); + Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); + Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); + return Builder.CreateBitCast(Res, Ops.LHS->getType()); + } + + return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); + } else { + // pointer - pointer + Value *LHS = Ops.LHS; + Value *RHS = Ops.RHS; + + uint64_t ElementSize; + + // Handle GCC extension for pointer arithmetic on void* and function pointer + // types. + if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { + ElementSize = 1; + } else { + ElementSize = CGF.getContext().getTypeSize(LHSElementType) / 8; + } + + const llvm::Type *ResultType = ConvertType(Ops.Ty); + LHS = Builder.CreatePtrToInt(LHS, ResultType, "sub.ptr.lhs.cast"); + RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); + Value *BytesBetween = Builder.CreateSub(LHS, RHS, "sub.ptr.sub"); + + // Optimize out the shift for element size of 1. + if (ElementSize == 1) + return BytesBetween; + + // HACK: LLVM doesn't have an divide instruction that 'knows' there is no + // remainder. As such, we handle common power-of-two cases here to generate + // better code. See PR2247. + if (llvm::isPowerOf2_64(ElementSize)) { + Value *ShAmt = + llvm::ConstantInt::get(ResultType, llvm::Log2_64(ElementSize)); + return Builder.CreateAShr(BytesBetween, ShAmt, "sub.ptr.shr"); + } + + // Otherwise, do a full sdiv. + Value *BytesPerElt = llvm::ConstantInt::get(ResultType, ElementSize); + return Builder.CreateSDiv(BytesBetween, BytesPerElt, "sub.ptr.div"); + } +} + +Value *ScalarExprEmitter::EmitShl(const BinOpInfo &Ops) { + // LLVM requires the LHS and RHS to be the same type: promote or truncate the + // RHS to the same size as the LHS. + Value *RHS = Ops.RHS; + if (Ops.LHS->getType() != RHS->getType()) + RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); + + return Builder.CreateShl(Ops.LHS, RHS, "shl"); +} + +Value *ScalarExprEmitter::EmitShr(const BinOpInfo &Ops) { + // LLVM requires the LHS and RHS to be the same type: promote or truncate the + // RHS to the same size as the LHS. + Value *RHS = Ops.RHS; + if (Ops.LHS->getType() != RHS->getType()) + RHS = Builder.CreateIntCast(RHS, Ops.LHS->getType(), false, "sh_prom"); + + if (Ops.Ty->isUnsignedIntegerType()) + return Builder.CreateLShr(Ops.LHS, RHS, "shr"); + return Builder.CreateAShr(Ops.LHS, RHS, "shr"); +} + +Value *ScalarExprEmitter::EmitCompare(const BinaryOperator *E,unsigned UICmpOpc, + unsigned SICmpOpc, unsigned FCmpOpc) { + TestAndClearIgnoreResultAssign(); + Value *Result; + QualType LHSTy = E->getLHS()->getType(); + if (!LHSTy->isAnyComplexType() && !LHSTy->isVectorType()) { + Value *LHS = Visit(E->getLHS()); + Value *RHS = Visit(E->getRHS()); + + if (LHS->getType()->isFloatingPoint()) { + Result = Builder.CreateFCmp((llvm::CmpInst::Predicate)FCmpOpc, + LHS, RHS, "cmp"); + } else if (LHSTy->isSignedIntegerType()) { + Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)SICmpOpc, + LHS, RHS, "cmp"); + } else { + // Unsigned integers and pointers. + Result = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHS, RHS, "cmp"); + } + } else if (LHSTy->isVectorType()) { + Value *LHS = Visit(E->getLHS()); + Value *RHS = Visit(E->getRHS()); + + if (LHS->getType()->isFPOrFPVector()) { + Result = Builder.CreateVFCmp((llvm::CmpInst::Predicate)FCmpOpc, + LHS, RHS, "cmp"); + } else if (LHSTy->isUnsignedIntegerType()) { + Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)UICmpOpc, + LHS, RHS, "cmp"); + } else { + // Signed integers and pointers. + Result = Builder.CreateVICmp((llvm::CmpInst::Predicate)SICmpOpc, + LHS, RHS, "cmp"); + } + return Result; + } else { + // Complex Comparison: can only be an equality comparison. + CodeGenFunction::ComplexPairTy LHS = CGF.EmitComplexExpr(E->getLHS()); + CodeGenFunction::ComplexPairTy RHS = CGF.EmitComplexExpr(E->getRHS()); + + QualType CETy = LHSTy->getAsComplexType()->getElementType(); + + Value *ResultR, *ResultI; + if (CETy->isRealFloatingType()) { + ResultR = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, + LHS.first, RHS.first, "cmp.r"); + ResultI = Builder.CreateFCmp((llvm::FCmpInst::Predicate)FCmpOpc, + LHS.second, RHS.second, "cmp.i"); + } else { + // Complex comparisons can only be equality comparisons. As such, signed + // and unsigned opcodes are the same. + ResultR = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHS.first, RHS.first, "cmp.r"); + ResultI = Builder.CreateICmp((llvm::ICmpInst::Predicate)UICmpOpc, + LHS.second, RHS.second, "cmp.i"); + } + + if (E->getOpcode() == BinaryOperator::EQ) { + Result = Builder.CreateAnd(ResultR, ResultI, "and.ri"); + } else { + assert(E->getOpcode() == BinaryOperator::NE && + "Complex comparison other than == or != ?"); + Result = Builder.CreateOr(ResultR, ResultI, "or.ri"); + } + } + + return EmitScalarConversion(Result, CGF.getContext().BoolTy, E->getType()); +} + +Value *ScalarExprEmitter::VisitBinAssign(const BinaryOperator *E) { + bool Ignore = TestAndClearIgnoreResultAssign(); + + // __block variables need to have the rhs evaluated first, plus this should + // improve codegen just a little. + Value *RHS = Visit(E->getRHS()); + LValue LHS = EmitLValue(E->getLHS()); + + // Store the value into the LHS. Bit-fields are handled specially + // because the result is altered by the store, i.e., [C99 6.5.16p1] + // 'An assignment expression has the value of the left operand after + // the assignment...'. + if (LHS.isBitfield()) { + if (!LHS.isVolatileQualified()) { + CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType(), + &RHS); + return RHS; + } else + CGF.EmitStoreThroughBitfieldLValue(RValue::get(RHS), LHS, E->getType()); + } else + CGF.EmitStoreThroughLValue(RValue::get(RHS), LHS, E->getType()); + if (Ignore) + return 0; + return EmitLoadOfLValue(LHS, E->getType()); +} + +Value *ScalarExprEmitter::VisitBinLAnd(const BinaryOperator *E) { + // If we have 0 && RHS, see if we can elide RHS, if so, just return 0. + // If we have 1 && X, just emit X without inserting the control flow. + if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { + if (Cond == 1) { // If we have 1 && X, just emit X. + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + // ZExt result to int. + return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "land.ext"); + } + + // 0 && RHS: If it is safe, just elide the RHS, and return 0. + if (!CGF.ContainsLabel(E->getRHS())) + return llvm::Constant::getNullValue(CGF.LLVMIntTy); + } + + llvm::BasicBlock *ContBlock = CGF.createBasicBlock("land.end"); + llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("land.rhs"); + + // Branch on the LHS first. If it is false, go to the failure (cont) block. + CGF.EmitBranchOnBoolExpr(E->getLHS(), RHSBlock, ContBlock); + + // Any edges into the ContBlock are now from an (indeterminate number of) + // edges from this first condition. All of these values will be false. Start + // setting up the PHI node in the Cont Block for this. + llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); + PN->reserveOperandSpace(2); // Normal case, two inputs. + for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); + PI != PE; ++PI) + PN->addIncoming(llvm::ConstantInt::getFalse(), *PI); + + CGF.EmitBlock(RHSBlock); + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + + // Reaquire the RHS block, as there may be subblocks inserted. + RHSBlock = Builder.GetInsertBlock(); + + // Emit an unconditional branch from this block to ContBlock. Insert an entry + // into the phi node for the edge with the value of RHSCond. + CGF.EmitBlock(ContBlock); + PN->addIncoming(RHSCond, RHSBlock); + + // ZExt result to int. + return Builder.CreateZExt(PN, CGF.LLVMIntTy, "land.ext"); +} + +Value *ScalarExprEmitter::VisitBinLOr(const BinaryOperator *E) { + // If we have 1 || RHS, see if we can elide RHS, if so, just return 1. + // If we have 0 || X, just emit X without inserting the control flow. + if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getLHS())) { + if (Cond == -1) { // If we have 0 || X, just emit X. + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + // ZExt result to int. + return Builder.CreateZExt(RHSCond, CGF.LLVMIntTy, "lor.ext"); + } + + // 1 || RHS: If it is safe, just elide the RHS, and return 1. + if (!CGF.ContainsLabel(E->getRHS())) + return llvm::ConstantInt::get(CGF.LLVMIntTy, 1); + } + + llvm::BasicBlock *ContBlock = CGF.createBasicBlock("lor.end"); + llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("lor.rhs"); + + // Branch on the LHS first. If it is true, go to the success (cont) block. + CGF.EmitBranchOnBoolExpr(E->getLHS(), ContBlock, RHSBlock); + + // Any edges into the ContBlock are now from an (indeterminate number of) + // edges from this first condition. All of these values will be true. Start + // setting up the PHI node in the Cont Block for this. + llvm::PHINode *PN = llvm::PHINode::Create(llvm::Type::Int1Ty, "", ContBlock); + PN->reserveOperandSpace(2); // Normal case, two inputs. + for (llvm::pred_iterator PI = pred_begin(ContBlock), PE = pred_end(ContBlock); + PI != PE; ++PI) + PN->addIncoming(llvm::ConstantInt::getTrue(), *PI); + + // Emit the RHS condition as a bool value. + CGF.EmitBlock(RHSBlock); + Value *RHSCond = CGF.EvaluateExprAsBool(E->getRHS()); + + // Reaquire the RHS block, as there may be subblocks inserted. + RHSBlock = Builder.GetInsertBlock(); + + // Emit an unconditional branch from this block to ContBlock. Insert an entry + // into the phi node for the edge with the value of RHSCond. + CGF.EmitBlock(ContBlock); + PN->addIncoming(RHSCond, RHSBlock); + + // ZExt result to int. + return Builder.CreateZExt(PN, CGF.LLVMIntTy, "lor.ext"); +} + +Value *ScalarExprEmitter::VisitBinComma(const BinaryOperator *E) { + CGF.EmitStmt(E->getLHS()); + CGF.EnsureInsertPoint(); + return Visit(E->getRHS()); +} + +//===----------------------------------------------------------------------===// +// Other Operators +//===----------------------------------------------------------------------===// + +/// isCheapEnoughToEvaluateUnconditionally - Return true if the specified +/// expression is cheap enough and side-effect-free enough to evaluate +/// unconditionally instead of conditionally. This is used to convert control +/// flow into selects in some cases. +static bool isCheapEnoughToEvaluateUnconditionally(const Expr *E) { + if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) + return isCheapEnoughToEvaluateUnconditionally(PE->getSubExpr()); + + // TODO: Allow anything we can constant fold to an integer or fp constant. + if (isa<IntegerLiteral>(E) || isa<CharacterLiteral>(E) || + isa<FloatingLiteral>(E)) + return true; + + // Non-volatile automatic variables too, to get "cond ? X : Y" where + // X and Y are local variables. + if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) + if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) + if (VD->hasLocalStorage() && !VD->getType().isVolatileQualified()) + return true; + + return false; +} + + +Value *ScalarExprEmitter:: +VisitConditionalOperator(const ConditionalOperator *E) { + TestAndClearIgnoreResultAssign(); + // If the condition constant folds and can be elided, try to avoid emitting + // the condition and the dead arm. + if (int Cond = CGF.ConstantFoldsToSimpleInteger(E->getCond())){ + Expr *Live = E->getLHS(), *Dead = E->getRHS(); + if (Cond == -1) + std::swap(Live, Dead); + + // If the dead side doesn't have labels we need, and if the Live side isn't + // the gnu missing ?: extension (which we could handle, but don't bother + // to), just emit the Live part. + if ((!Dead || !CGF.ContainsLabel(Dead)) && // No labels in dead part + Live) // Live part isn't missing. + return Visit(Live); + } + + + // If this is a really simple expression (like x ? 4 : 5), emit this as a + // select instead of as control flow. We can only do this if it is cheap and + // safe to evaluate the LHS and RHS unconditionally. + if (E->getLHS() && isCheapEnoughToEvaluateUnconditionally(E->getLHS()) && + isCheapEnoughToEvaluateUnconditionally(E->getRHS())) { + llvm::Value *CondV = CGF.EvaluateExprAsBool(E->getCond()); + llvm::Value *LHS = Visit(E->getLHS()); + llvm::Value *RHS = Visit(E->getRHS()); + return Builder.CreateSelect(CondV, LHS, RHS, "cond"); + } + + + llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); + llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); + llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); + Value *CondVal = 0; + + // If we don't have the GNU missing condition extension, emit a branch on + // bool the normal way. + if (E->getLHS()) { + // Otherwise, just use EmitBranchOnBoolExpr to get small and simple code for + // the branch on bool. + CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); + } else { + // Otherwise, for the ?: extension, evaluate the conditional and then + // convert it to bool the hard way. We do this explicitly because we need + // the unconverted value for the missing middle value of the ?:. + CondVal = CGF.EmitScalarExpr(E->getCond()); + + // In some cases, EmitScalarConversion will delete the "CondVal" expression + // if there are no extra uses (an optimization). Inhibit this by making an + // extra dead use, because we're going to add a use of CondVal later. We + // don't use the builder for this, because we don't want it to get optimized + // away. This leaves dead code, but the ?: extension isn't common. + new llvm::BitCastInst(CondVal, CondVal->getType(), "dummy?:holder", + Builder.GetInsertBlock()); + + Value *CondBoolVal = + CGF.EmitScalarConversion(CondVal, E->getCond()->getType(), + CGF.getContext().BoolTy); + Builder.CreateCondBr(CondBoolVal, LHSBlock, RHSBlock); + } + + CGF.EmitBlock(LHSBlock); + + // Handle the GNU extension for missing LHS. + Value *LHS; + if (E->getLHS()) + LHS = Visit(E->getLHS()); + else // Perform promotions, to handle cases like "short ?: int" + LHS = EmitScalarConversion(CondVal, E->getCond()->getType(), E->getType()); + + LHSBlock = Builder.GetInsertBlock(); + CGF.EmitBranch(ContBlock); + + CGF.EmitBlock(RHSBlock); + + Value *RHS = Visit(E->getRHS()); + RHSBlock = Builder.GetInsertBlock(); + CGF.EmitBranch(ContBlock); + + CGF.EmitBlock(ContBlock); + + if (!LHS || !RHS) { + assert(E->getType()->isVoidType() && "Non-void value should have a value"); + return 0; + } + + // Create a PHI node for the real part. + llvm::PHINode *PN = Builder.CreatePHI(LHS->getType(), "cond"); + PN->reserveOperandSpace(2); + PN->addIncoming(LHS, LHSBlock); + PN->addIncoming(RHS, RHSBlock); + return PN; +} + +Value *ScalarExprEmitter::VisitChooseExpr(ChooseExpr *E) { + return Visit(E->getChosenSubExpr(CGF.getContext())); +} + +Value *ScalarExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { + llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); + llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); + + // If EmitVAArg fails, we fall back to the LLVM instruction. + if (!ArgPtr) + return Builder.CreateVAArg(ArgValue, ConvertType(VE->getType())); + + // FIXME Volatility. + return Builder.CreateLoad(ArgPtr); +} + +Value *ScalarExprEmitter::VisitBlockExpr(const BlockExpr *BE) { + return CGF.BuildBlockLiteralTmp(BE); +} + +//===----------------------------------------------------------------------===// +// Entry Point into this File +//===----------------------------------------------------------------------===// + +/// EmitScalarExpr - Emit the computation of the specified expression of +/// scalar type, ignoring the result. +Value *CodeGenFunction::EmitScalarExpr(const Expr *E, bool IgnoreResultAssign) { + assert(E && !hasAggregateLLVMType(E->getType()) && + "Invalid scalar expression to emit"); + + return ScalarExprEmitter(*this, IgnoreResultAssign) + .Visit(const_cast<Expr*>(E)); +} + +/// EmitScalarConversion - Emit a conversion from the specified type to the +/// specified destination type, both of which are LLVM scalar types. +Value *CodeGenFunction::EmitScalarConversion(Value *Src, QualType SrcTy, + QualType DstTy) { + assert(!hasAggregateLLVMType(SrcTy) && !hasAggregateLLVMType(DstTy) && + "Invalid scalar expression to emit"); + return ScalarExprEmitter(*this).EmitScalarConversion(Src, SrcTy, DstTy); +} + +/// EmitComplexToScalarConversion - Emit a conversion from the specified +/// complex type to the specified destination type, where the destination +/// type is an LLVM scalar type. +Value *CodeGenFunction::EmitComplexToScalarConversion(ComplexPairTy Src, + QualType SrcTy, + QualType DstTy) { + assert(SrcTy->isAnyComplexType() && !hasAggregateLLVMType(DstTy) && + "Invalid complex -> scalar conversion"); + return ScalarExprEmitter(*this).EmitComplexToScalarConversion(Src, SrcTy, + DstTy); +} + +Value *CodeGenFunction::EmitShuffleVector(Value* V1, Value *V2, ...) { + assert(V1->getType() == V2->getType() && + "Vector operands must be of the same type"); + unsigned NumElements = + cast<llvm::VectorType>(V1->getType())->getNumElements(); + + va_list va; + va_start(va, V2); + + llvm::SmallVector<llvm::Constant*, 16> Args; + for (unsigned i = 0; i < NumElements; i++) { + int n = va_arg(va, int); + assert(n >= 0 && n < (int)NumElements * 2 && + "Vector shuffle index out of bounds!"); + Args.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, n)); + } + + const char *Name = va_arg(va, const char *); + va_end(va); + + llvm::Constant *Mask = llvm::ConstantVector::get(&Args[0], NumElements); + + return Builder.CreateShuffleVector(V1, V2, Mask, Name); +} + +llvm::Value *CodeGenFunction::EmitVector(llvm::Value * const *Vals, + unsigned NumVals, bool isSplat) { + llvm::Value *Vec + = llvm::UndefValue::get(llvm::VectorType::get(Vals[0]->getType(), NumVals)); + + for (unsigned i = 0, e = NumVals; i != e; ++i) { + llvm::Value *Val = isSplat ? Vals[0] : Vals[i]; + llvm::Value *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty, i); + Vec = Builder.CreateInsertElement(Vec, Val, Idx, "tmp"); + } + + return Vec; +} |
